The present invention relates to a process for varnishing cards equipped with connecting pins, as well as to the card obtained in this way.
Electronic circuits are generally carried by cards on which are produced printed circuits for interconnecting components or integrated circuits arranged on the card. Interconnection can also take place by means of wrappings. These cards are frequently plugged in parallel to one another to an interconnecting card called a "mother card", whilst the cards carrying the circuits are called "daughter cards". The mother card comprises male connectors constituted by pins welded with a standard pitch to a substrate provided with metallized holes. Part of the pin is used for plugging in the cards and the other shorter part passing from the other side of the substrate can be used for interconnection in the case of cable connections.
With the object of increasing the electrical insulation and protecting the substrate without impairing the contact quality of the pins it is known to varnish or lacquer cards by using, prior to exposure a mask which protects the weld points at the location of the metallized holes. This procedure only permits a partial protection because the location of the welds where the pins are to be positioned is not protected by the varnish. Thus, these parts are not protected against corrosion and are not electrically insulated.